Caliphate

Caliph (خليفة) was the title taken by Abu Bakr, the father-in-law of Muhammad, when he succeeded him as leader of the Ummah, or community of Islam, in 632.
The title has the implication of ruler of all the Islamic world.

Following the conflict between the Fatimids and the Abbasids, other Muslim rulers began to claim the caliphal title. With defeat of these peripheral caliphates, the caliphate of the Ottomans began increasingly to be considered to be undisputed primary caliphate.
Thus, by eve of the First World War the Ottoman caliphate represented the largest and most powerful independent Islamicate political entity.

The word "Caliph" came through French, which got it from Latin (calīpha), a Romanization of the Arabic word, Khalīfa (probably خليفة), literally "Successor of the Prophet." Khalīfa originates from the verbkhalafa, meaning "to succeed" or "to be behind."
Some Orientalists wrote it as Khalîf.
Some movements in modern Islamic philosophy justify religious leadership via khalifa, meaning roughly "to steward" or "to protect the same things as God," and propose this to renew the Caliphate.

After the sack of Baghdad by the Mongols in 1258, the Mamluk rulers of Egypt set up an Abbasid as a puppet Caliph in Cairo. These Caliphs lasted until the Ottoman conquest in 1517

In the 19th Century, the Ottoman Sultans began to claim the title of Caliph, saying that it had been passed from the last Abbasid to Sultan Selim I, although there is no evidence of this. After the abolition of the Sultanate in 1922, the Caliphate continued for two more years under the Ottoman Prince Abdul Mejid II, before being finally abolished at the behest of Kemel by the Grand National Assembly in 1924.